The invention relates generally to semiconductor integrated circuits, and more particularly, to a spherical shaped semiconductor integrated circuit and a system and method for manufacturing same.
Conventional integrated circuits, or xe2x80x9cchipsxe2x80x9d, are formed from a flat surface semiconductor wafer. The semiconductor wafer is first manufactured in a semiconductor material manufacturing facility and is then provided to a fabrication facility, or xe2x80x9cfab.xe2x80x9d At the fab, several layers are processed onto the semiconductor wafer surface. Once completed, the wafer is then cut into one or more chips and assembled into packages. Although the processed chip includes several layers fabricated thereon, the chip still remains relatively flat.
To own and operate a modern wafer manufacturing facility, fab, and assembly facility, tremendous resources must be assembled. For example, a single fab typically cost several billion dollars, and therefore requires a great deal of capital and commitment. This high level of capital and commitment is compounded by many problems inherent to both chips and fabs.
Many of these problems reflect on the enormous effort and expense required for creating silicon wafers and chips. For example, manufacturing the wafers requires creating rod-form polycrystalline semiconductor material; precisely cutting ingots from the semiconductor rods; cleaning and drying the cut ingots; manufacturing a large single crystal from the ingots by melting them in a quartz crucible; grinding, etching, and cleaning the sure of the crystal; cutting, lapping and polishing wafers from the crystal; and heat processing the wafers. Moreover, the wafers produced by the above process typically have many defects. These defects can be attributed to the difficulty in making a single, highly pure crystal due to the cutting, grinding and cleaning processes as well as impurities associated with containers used in forming the crystals. For example, oxygen is a pronounced impurity associated with the quartz crucible. These defects become more and more prevalent as the integrated circuits formed on these wafers contain smaller and smaller dimensions.
A problem associated with modern fabs is that they require many different large and expensive facilities. For example, fabs require dust-free clean rooms and temperature-controlled manufacturing and storage areas to prevent the wafers and chips from defecting and warping. The amount of dust in the clean rooms is directly proportional to the end quality of the chips. Also, warping is especially problematic during heat treatment processes.
Other problems associated with modern fabs result from their inherently inefficient throughput as well as their inefficient use of silicon. For example, modern fabs using in-batch manufacturing, where the wafers are processed by lots, must maintain huge inventories to efficiently utilize all the equipment of the fab. Also, because the wafers are round, and completed chips are rectangular, the peripheral portion of each wafer cannot be used.
Still another problem associated with modern fabs is that they do not produce chips that are ready to use. Instead, there are many additional steps that must be completed, including: cutting and separating the chip from the wafer, assembling the chip to a lead frame which includes wire bonding, plastic or ceramic molding and cutting and forming the leads, positioning the assembled chip onto a printed circuit board; and mounting the assembled chip to the printed circuit board. The cutting and assembly steps introduce many errors and defects due to the precise requirements of such operations. In addition, the positioning and mounting steps are naturally two-dimensional in character, and therefore do not support curved or three dimensional areas.
Therefore, due to these and various other problems, only a few companies in the world today can successfully manufacture conventional chips. Furthermore, the chips must bear a high price to cover the costs of manufacturing, as well as the return on initial capital and investment.
The present invention, accordingly, provides a spherical shaped semiconductor integrated circuit and a system and method for manufacturing same. The spherical shaped semiconductor integrated circuit, hereinafter xe2x80x9cballxe2x80x9d, replaces the function of the flat, conventional chip. The physical dimensions of the ball allow it to adapt to many different manufacturing processes which otherwise could not be used. Furthermore, the assembly and mounting of the ball facilitates efficient use of semiconductor material as well as circuit board space.
An advantage achieved with the present invention is that it supports semiconductor processing using wafting in a vacuum, gas or liquid. Such wafting may be in a vertical, horizontal or diagonal direction.
Another advantage achieved with the present invention is that it supports semiconductor processing while the ball is moving through a pipe, tube, or container. Such movement may be in a vertical, horizontal or diagonal direction. Furthermore, the pipe or tube can be continuous, thereby reducing or eliminating the need for a clean room environment.
Another advantage achieved with the present invention is that it supports semiconductor processing at ultra-high temperatures, including such temperatures at or above conventional semiconductor material warping or melting points.
Another advantage achieved with the present invention is that it facilitates crystal formation in that a spherical crystal is naturally formed by its own surface tension.
Another advantage achieved with the present invention is that the spherical shape of the ball provides much greater surface area on which to inscribe the circuit.
Another advantage achieved. with the present invention is that the spherical shape of the ball withstands external forces better than the conventional chip. As a result, conventional assembly packaging is not always required with the ball.
Another advantage achieved with the present invention is that the spherical shape of the ball allows one ball to be connected directly to a circuit board or clustered with another ball. Such clustering enables three-dimensional multi-active layers and multi-metal layers in any direction.
Another advantage achieved with the present invention is that it allows a single, relatively small facility to manufacture the semiconductor material as well as perform the fabrication. Furthermore, the requirements for assembly and packaging facilities are eliminated.
Another advantage achieved with the present invention is that it reduces manufacture cycle time.
Another advantage achieved with the present invention is that a single fabrication structure can be commonly used for many different processing steps.
Other advantages, too numerous to mention, will be well appreciated by those skilled in the art of semiconductor fabrication.